QFT robust controller design and experiment research of electro-hydraulic driving parallel robot

Electro-hydraulic driving 6-dof parallel robot suffers from non-linearity, strong load coupling disturbance and parameters variations when it moves. In order to solve the problem of precise trajectory tracking for 6-dof parallel robot, a decentralized control strategy was used and a 2-dof QFT robust controller was designed in the joint space of robot. Experiment results show that the 2-dof QFT robust controller is strongly robust for parameters variations, has the ability of attenuating load coupling disturbance force among channels and realizes the trajectory tracking precisely. This control method proposed here has a universal application value for the robust control system design of other parallel robots.